Interconnected lamp socket



July 13 1926. 1,592,620

E. S. PRESTON INTERGONNEC'IED LAMP SOCKET Filed July 23. 1923 2Sheets-Sheet 1 July 13,1926. 1,592,620

- E. S. PRESTQN INTERCONNECTED LAMP SOCKET Filed July 23, 1923 2Sheets-Sheet 2 Patented July 13, 19 26.

UNITED STATES 1,592,620 PATENT OFFICE.

EDWARD S. PRESTON, OF CHICAGO, ILLINOIS, ASSIGNOB, BY HISHE ASSIGNMENTS,

TO CHICAGO ELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A COB-roan-11101101 rumors.

INTEBCONNECTED LAMP SOCKET.

Application 'flled July 2 1928. Serial No. 658,106.

My invention relates to sockets for electric lamps and to circuitconnections between them for enablin one lamp socket to providedetachable circuit connections for another socket also.

In one broad aspect, my invention aims to provide a lamp socketemploying a substantially flat perforated supporting portion as themeans for receiving and interlocking with the lamp base. For thispurpose, my invention provides a construction which can readily bemanufactured from sheet metal by a simple punch-press operation forserving as such a lamp support, which can readily be equipped withintegral means for preventing an attached lamp from rocking, and whichwill ermit another circuit connection to be secured to it in such amanner that the combination will aflord an elfective lamp-socket ofunusually short length. Fur thermore, my invention provides a socketconstruction of this class in which the conducting member employed forcarrying the current to the axial contact of the lamp is so arrangedthat this conducting member can readily serve also as the means forconveyin the current from a circuit terminal space from the socket. v

In another broad aspect, my invention provides an arrangement ofinter-connected lamp sockets whic will permit one of the sockets to beused in combination with a wire-terminal plug for carrying the currentfrom separate circuits to lamps associated both with that main socketand with another or auxiliary lamp-socket.

For this purpose, in invention provides a 'main socket equippe forholding a lamp having a single terminal at its rear end and forconveying current to this terminal from one terminal of a to thatsocket; it also provides conducting means arranged for receiving currentfrom the other terminal of the plug and extending beyond the socketwithout interfering with the read attaching of the lamp to that socket.lurthermore, it provides a twin socket construction for this purpose inwhich the said conducting means may also serve as a lamp-contactinportion of the companion or auxiliary soc et, and provides simple meansfor suitably insulating the conducting means. v J

More particularly, my invention provides two-wire plug connected theupper lamp socket.

a two-light socket assembly adapted for use with a pair of groundedcircuits and so arranged that the two circuit wires can readily beconnected to one of the sockets by means of an ordinary two-wireattaching plug, the

last named socket being equipped both with means for carrying thecurrent from one terminal of the plug to a lamp interlocked with thatsocket and'for carrying current from the other terminal direct to thelampcontacting terminal of the other socket. Still further and also moredetailed objects will appear from the following specification and fromthe accompanying drawings, in which Fig. 1 is a side elevation showing asocket, lamp and plug assembly embodying my invention.

Fig. 2 is a perspective view of the same with the lamps and thewire-terminal plug detached. Fig. 3 is a fragmentary plan view of thesame embodiment.

Fig. 4 is a section through the same embodiment taken along the line 4-4of Figs. 1 or 3.

Fig. 5 is a transverse central and transverse section taken along thelines 5-5 of Figs. 2 and 4 and showing the assembly with thewireterminal lug in its attached position, but with hot lamps detached.

Fig. 6 is a fragmentary perspective view of the metal plate whichconstitutes one of the main portions of the upper. lamp socket.

Fig. 7 is a bottom view of the metal condufiting member of the upperlamp socket, an

Fig. 8 is a side elevation of the same taken from the left hand of Fig.7.

Fig. 9 is a fragmentary section taken through Fig. 5 along the line 9-9of that figure to show the connection between one current-receivingmember of the lower lamp socket and the insulated contact member of Inone of its commercial applications, my invention is particularly adaptedfor embodiment in two-light lamps as employed for afiordin both thecontinuously burning tail light 0% an automobile and the intermittentlylighted stop signal, as for instance a lam of t 'e general ty edisclosed in my copen app 'cation 0. 653,105, filed July 23rd, 1323, ona combination tail and stop lamp. I am therefore illustrating variousfeatures of my invention in an embodiment particularly suited for suchuses, although I do not wish to be limited to the employment of myinvention in connection with any particular type of lamp or for anyparticular purpose.

Where a series of separately controlled lights are employed on avehicle, it has been customary for many years to ground one side of eachcircuit and to employ only asingle wire for making the other circuitconnection to a socket, the connection from this I equip one of thesockets so that it will cooperate with a two-wire terminal plug andprovide such conductmg means that the circuit connections afforded bythe mere at taching of the plug will carry the current respectively tothe axial terminals of the two lamps.

Thus, I desirably rovide an assembly which holds both of t e lampsockets in a rigidly fixed relation and preferably ar= range thisassembl so as to afford a unit which can readily e attached to lampcasings of various types. For example, the drawings show this mountingas including a supporting member comprising a horizontal web. 1constructed integral with a. depending vertical web 2, the latter havinga rearwardly directed collar 3 formed upon the same. This collar 3houses a medial portion of a socket shell 4 equipped at its forward endwith bayonet slots 5 for receiving the anchoring ins 6 on the base of alamp 7, the said shell also having at its rear end bayonet slots 7 forreceiving the corresponding lateral pins 8 on a wire terminal plug 9 towhich the two ungrounded circuit wires 10 and 11 are attached.

The socket shell 4 has mounted within it the usual insulating core orbody 11 housing a metal cylinder 12 which in turn houses a compressionspring 13 disposed between a forwardly pro ecting plunger 14 and arearwardly projecting plunger 15. Instead of being disposed axiall ofthe insulating body 11 and of the soc et shell 4, this cylinder 12extends at an angle to the axis of the shell, so that the tip of theforward plunger 14 is disposed substantialy axially of the shell orinposition for contacting with the usual axial terminal of the lamp 7,while the rearwardly projecting plunger 15 is disposed for engaging thewire terminal 16 ple room for having the insulating body carry a secondcylinder 17 which desirably extends parallel to the axis of the socketshell at one side of the latter. This cylinder 17 houses a "compressionspring 18 which continuously urges a plunger 19 rearwardly of the socketand into engagement with the forward end of a wire terminal 20 alsocarried by the plug 9 and connected to the wire 10 of the other circuit.

For the companion or auxiliary socket I desirably employ a compactstructure in .Which the lamp=holding parts are formed largely bypunchinlgr operations upon the horizontal web 1. or this purpose, I am\showing this plate 1 as provided with a .cylindrical perforation 21closely approximating the outside diameter of .the base 22 of thecompanion lam 23, this erforation being enlarged at two 'ametrical yopposite points by recesses 24 through which the usual anchoring pins25on the lamp base 22 may enter. Then- I also form from the plate 1 a pairof downwardly open pocket formations 26 into which the said anchoringpins 25 are adapted to snap when the lamp base has been partiallyrotated after the pins have passed downwardly through the recesses 24. lW

Instead of employing a spring-pressed plunger construction for engaginthe axial contact 27 of this upper lamp, desirably employ a springfinger 28 formed upon a conducting member stamped from resilient sheetmetal, which member desirably has one of its parts connected directly tothe cylinder 17. For this pur ose, I am here show- 1ng a conducting memer comprising a ring a resilient finger 28 portion 29 havin formed fromone e e thereof and extending across the axis of t e ring, and having atits opposite edge a depending finger 30 which extends through acorrespondingly disposed bore in the socket shell 4 and into a suitabletransverse perforation in the cylinder 17 The ring-shaped portion 29 ofthe said conducting member is disposed coaxially with the perforation 21and is suitably insulated from the metal plate 1, as for example bylower bushings 32 and upper washers 33 housing the shanks of the rivets34 by means of which the said ring shaped portion 29 is secured to theweb 1. The depending finger 30 is also insulated from the metalsupporting member, as by an insulating plate 35 which bears flatwiseagainst the vertical web 2 of the supporting member 35 to conform to aportion of the perip ery and which is clamped between the depend A ofthe socket shell 4 and by having the upper end of the insulating platefabut against the bottom of the metal plate 1, as shown in Fig. 2, Leanreadily ,cause the said clamping to hold the insulating plate in properoperative position without employing any auxiliary fastening elements,

To secure an adequate conducting connection between the finger 30 andthe cylinder 17, I desirably reduce the free end of this finger to atapering portion 36 which affords a driving fit when inserted in thetransverse bore 37 as formed in the cylinder 17, so that the mereassembling of these parts insures a firm and adequate electricalconnection.

When the upper lamp has its base inserted and partially rotated as abovedescribed, the resiliency of the sprin finger 28 which presses upwardlyagainst t e axial terminal 23 of the upper lamp holds the anchoring pins25 interlocked with the arched formations 26, thus affording a securesupporting of the lamp in a compact and exceedingly simple structure.However, the lamp might tend to rock about the axis of the anchoringpins 25. To guard against such a rocking movement, particularly when thelamp assembly is subjected to jarring, I desirably draw a couple ofupwardly extending guide flanges 38 from the metal out of which theplate 1 is formed, these guide flanges being concaved to correspond tothe bore of the perforation 21 and being at portions of this perforationwhich are at 1'1 ht angles to the common axis of the arch or- ;mations26.

With the socket amembly thus arranged, it will be obvious from Fig. 5that the upper socket construction is exceedingly compact and has itsgrounded metal rtion formed out of sheet metal integral with thevertical web 2 and the collar 3' through which the lower socket extends.Hence my said'assembly permits of mounting the two lamps relativelyclose to each other. Furthermore, since the electrical connection to theaxial terminal of the upper lamp is made directly from the plungercylinder 17 by the single conducting member which forms an operative andrmanently attached part of the upper soc et, no wiring, is required formaking the cross connection between the sockets. Indeed, the only wiringrequired is that of securing the two circuit wires 10 and 11' to thecorresponding wire terminals of the detachable plu by means of the usuallateral screws 39. go also, it will be obvious from the drawings thatthe assembly as pictured in Figs. 1 and 2 can readily be handled as aunit, being assembled in its entirety (either with or without attachingthe lamps b y to the same) before attaching this assem to a casing ofany kind. Moreover, since relatively short guide flanges 38 are employedfor preventing the upper lamp from rocking, I can provide a mountingwhich will afiord a relatively close spacing of the two lamps, therebypermitting the use of a casing of relatively small diameter.

However, while-I have illustrated and described the various features ofmy invention as combined in a single embodiment, I do not wish to belimited to the joint use of all of these features. to be limited to theparticular details of the construction and arrangement here described,it being obvious that the same might be modified in many ways withoutdeparting either from the spirit of my invention or from the appendedclaims. Furthermore, I am here claiming the feature of my presentedconstruction which include the sheet metal supporting member, thesebeing embodied in my copending divisional patent application, filed July1924, on interconnected lamp sockets.

ll claim as my invention Neither do I wish l. A twin-lamp socketincluding a base" having a vertical and a horizontal part, a Socketshell carried by the vertical part of the base, a conductor member inthe socket, an insulating plate abutting the inner face of said verticalpart and engaged at one end with the under face of the horizontal partof the base, said plate having its other end comfortably engaging thesocket shell, means to support a amp on the horizontalpart of the base,and a conducting member of the same angularity as that of the basesecured to said horizontal part of the base and having a part engagedwith the insulating plate to clamp same in position and also. havingelectrical contact with the first named conductor member, and with thelamp on the horizontal part of the base.

2. A twin-lamp socket including a substantially L-shaped base, means to,support a lamp on one of the arms of the base, a,

lamp receiving shell on the other arm, a contact in the shell, asubstantially L-shaped conductor plate having one end secured to thecorresponding arm of the base and havmg said and underlying the firstnamed arm and formed to engage the axial terminal of the first namedlamp, the other en of said conductor plate extending into the shell andbeing engaged with the contact no I thereof, and a contact in the shellfor the said member, the opposite end of the plate havinga ringregistering with and below the other lamp socket and having a resilienttongue extending across the ring and formed to directly engage the axialterminal of a lamp in the other socket, and

a lamp terminal engaging conductor in the first named socket. t

4. In a twin-lamp socket, a base having a horizontal and a "erticalpart, a lamp socket carried b the vertical part of said base so as toispose the lamp beneath the horizontal part, a lamp socket carried bythe horizontal part, a conductor member having a ringike part secured tothe under face of the horizontal part and having a contact tonguedisposed diametrically across the open center of the ring and beneaththe horizontal part to engage the lamp of the latter, said conductormember having a second contact part engaging the socket of the verticalpart of the base and means to insulate the conductor member from thebase.

5. In a twin-lamp socket, a base having a horizontal and a verticalpart, a lamp socket carried by the vertical part of said base so as todispose the lamp beneath the horizontal part, a lamp socket carried bythe horizontal part, a conductor member second contact part engaging thesocket of the vertical part of the base, and means to insulate the baseand conductor member.

6. A twin-lamp socket including a substantially Lshaped base, means tosupport a lamp on one of'the arms of the base, a lamp receivin shell onthe other arm, a contact in the s ell, a substantially L-shapedconductor plate having one endsecured to the'corresponding arm of thebase and having said end underlying the first named arm and formed toengage the axial terminal of the first named lamp, a conductor member inthe shell, the other end of said conductor plate being or" Wedge-shapeand wedgingly engaged in a slot provided therefor in the conductormember, and a contact in the shell for the axial terminal of the lampthereof,

Signed at Chicago, Illinois, July 16th, 1923.

EDWARD S. PRESTON.

